Packing box

Abstract

To provide a packaging box which reduces a repulsive force of a cardboard sheet, and which can be fixed in a state where an opening part is appropriately closed with flaps.SOLUTION: A packaging box 10 includes: a body part 2 in which side surface parts 3, 5, 7, 9 are connected in a cylindrical manner; and flaps 23, 25, 27, 29 which extend from opening sides 33, 35, 37, 39 of the side surface parts 3, 5, 7, 9, and close at least part of an opening part. The flaps are provided with at least: tip sides 43, 45, 47, 49; an inside surface; and an outside surface. The tip side of the outside surface is provided with: a dented line part 73, a first inclined parts 71, and first tip part 75 between the dented line part 73 and the tip side. The tip side of the inside surface is provided with: a second inclined part 77; and a second tip part 79 between the second inclined part 77 and the tip side. The second tip part 79 is provided on the tip side of the dented line part 73.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a packaging box made of corrugated cardboard sheet suitable for use in packaging products and the like. [Background technology]

[0002] Conventionally, a packaging box has been known that has a main body formed by folding a cardboard sheet into a cylindrical shape and lid flaps extending from the edges of the main body to close the top and bottom openings. Also known is a wrap-around type packaging box in which a cardboard sheet is folded along the periphery of a product and the sides are covered with flaps extending from the edges of the cardboard sheet that surround the periphery of the product (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-370728 Summary of the Invention [Problem to be solved by the invention]

[0004] In a conventional packaging box with lid flaps that close the top and bottom openings, a pair of inner flaps and a pair of outer flaps extend from the edge of the main body near the opening. When packaging a product or the like, after the product or other contents are placed inside the main body through the opening, the inner flaps are folded at their borders with the main body to close a portion of the opening (hereinafter, the state in which the flaps close the opening will also be referred to as the "closed state"). Next, the outer flaps are folded at their borders with the main body so as to overlap the folded inner flaps, thereby closing the box. Then, adhesive tape is applied across the leading ends of the outer flaps to secure the outer flaps in the closed state.

[0005] In the conventional packaging boxes described above, there was a problem that the outer flaps secured with adhesive tape would lift up due to the repulsive force of the cardboard sheet. Furthermore, when closing the opening with the outer flaps, there was also a problem that the leading ends of the flaps would sometimes overlap and be secured with adhesive tape. In these cases, the central portion of the surface closed by the outer flaps would be raised, which not only worsened the appearance but also reduced the stability of the packaging box. For example, there was a problem of reduced stability when multiple packaging boxes were stacked.

[0006] The present disclosure aims to provide a packaging box that reduces the repulsive force of a cardboard sheet and can secure an opening in an appropriately closed state with a flap. [Means for solving the problem]

[0007] To achieve the above object, the present disclosure provides the following means. The packaging box of the present disclosure is a packaging box made of cardboard sheet, and is provided with a main body portion having a plurality of side portions connected in a cylindrical shape and having an opening surrounded by the side portions, and a flap extending from an opening edge that is the edge of the side portion on the side of the opening and closing at least a part of the opening, the flap having at least a front side edge that extends approximately parallel to the opening edge on the front side in the direction in which the flap extends, an inner side surface that faces inward and to which the side portions of the main body portion face when the opening is closed, and an outer side surface on the opposite side to the inner side surface, and the front part of the outer side surface has a width that is larger than the front side edge. The inner surface has a recessed line portion recessed inward, extending approximately parallel to the tip side edge at a predetermined distance from the opening edge, a first inclined portion extending inward from the opening edge toward the recessed line portion in an area closer to the opening edge than the recessed line portion, and a first tip portion between the recessed line portion and the tip side edge, and the tip side portion of the inner surface has a second inclined portion extending outward and inclining toward the tip side, and a second tip portion between the second inclined portion and the tip side edge, and the second tip portion is located on the tip side of the recessed line portion.

[0008] According to the packaging box of the present disclosure, a first inclined surface and a second inclined surface are provided at the leading portions of the outer and inner surfaces of the flaps that close the opening of the main body. The leading portion of the outer surface is provided with an inwardly recessed line and a first leading portion. Furthermore, the leading portion of the inner surface is provided with a second leading portion further forward of the recessed line. That is, the leading portions of the flaps of the packaging box of the present disclosure are each formed with a predetermined shape on the outer and inner surfaces, and are configured so that their thickness decreases toward the leading portion. This reduces the repulsive force of the cardboard sheet at the leading portion of the flaps. Furthermore, when the flaps are secured with adhesive tape, the outer corners of the flap tips are prevented from protruding outward. Furthermore, even if the flaps are closed with their leading portions overlapping, it is expected that the leading portions of each flap will deform, causing the overlapping flaps to naturally shift and eliminate the leading overlap.

[0009] In the above disclosure, it is preferable that the first tip portion extends toward the tip side at a different angle than the first inclined portion, and the second tip portion extends toward the tip side at a different angle than the second inclined portion.

[0010] This reduces the repulsive force of the cardboard sheet at the leading edge of the flaps. Even if the flaps are closed with their leading edges overlapping, the force acting on the flaps is distributed between the first and second leading edges, so that the overlapping flaps will naturally shift and the overlap at the leading edges will be resolved.

[0011] In the above disclosure, it is preferable that the first inclined portion extends in a more inwardly inclined manner from the side of the opening than the second inclined portion.

[0012] By doing this, the leading portion of the outer surface of the flap is inclined over a wider range than the leading portion of the inner surface, further reducing the repulsive force of the cardboard sheet on the flap when the opening is closed. [Effects of the Invention]

[0013] The packaging box of the present disclosure has the effect of providing a packaging box that reduces the repulsive force of the cardboard sheet and can secure the opening in an appropriately closed state with a flap. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view illustrating a packaging box according to an embodiment of the present invention. [Figure 2] FIG. 1 is a perspective view illustrating a packaging box according to an embodiment of the present invention. [Figure 3] FIG. 2 is a diagram showing the front surface (outer surface) of the developed view of the packaging box according to the present embodiment. [Figure 4] FIG. 2 is a diagram showing the rear surface (inner surface) of the developed view of the packaging box according to the present embodiment. [Figure 5] FIG. 10 is a diagram showing an example of a cross section of a flap. [Figure 6] FIG. 10 is a diagram showing another example of a cross section of a flap. [Figure 7] FIG. 1 is a diagram illustrating a test. [Figure 8] Fig. 8(a) is a diagram showing a state where conventional packaging boxes fixed with adhesive tape are stacked, and Fig. 8(b) is a diagram showing a state where packaging boxes according to this embodiment fixed with adhesive tape are stacked. [Figure 9] Fig. 9(a) is a diagram showing a state where packaging boxes according to this embodiment fixed with adhesive tape are stacked, and Fig. 9(b) is a diagram showing a state where conventional packaging boxes fixed with adhesive tape are stacked. [Figure 10] Fig. 10(a) is a diagram illustrating a state in which a conventional packaging box is fixed with adhesive tape, and Fig. 10(b) is a diagram illustrating a state in which the packaging box according to this embodiment is fixed with adhesive tape. DETAILED DESCRIPTION OF THE INVENTION

[0015] A packaging box 10 according to an embodiment of the present disclosure will be described mainly with reference to FIGS. 1 to 10. In the following description, the front-rear, left-right, and top-bottom directions will refer to the directions shown in the drawings unless otherwise specified. The side of the packaging box 10 on which the product is stored will be referred to as the inside, and the opposite side as the outside. Furthermore, when the packaging box 10 is formed, the surface of the sheet material 1 that faces inward will be referred to as the inside surface or back surface, and the surface that faces outward will be referred to as the outside surface or front surface.

[0016] Arrows and diagonal lines indicating directions in each figure are provided to facilitate understanding of the relationship between the figures and the shapes of each component or part. Therefore, the contents shown in this disclosure are not limited to the directions indicated in each figure. Diagonal lines do not necessarily indicate cross-sectional views.

[0017] 1. Description of the configuration The packaging box 10 of this embodiment is a packaging box formed by folding at predetermined locations a sheet material 1 formed into the shape shown in Figures 3 and 4. In this embodiment, the sheet material 1 is a cardboard sheet.

[0018] The packaging box 10 includes a cylindrical main body 2 composed of rectangular side portions 3, 5, 7, and 9, flaps 23, 25, 27, and 29 that close an opening A on the upper side of the main body 2, and flaps 53, 55, 57, and 59 that close an opening B on the lower side of the main body 2. Opening B is not shown. Hereinafter, the flaps 23, 25, 27, and 29 and the flaps 53, 55, 57, and 59 will also be collectively referred to as "flaps."

[0019] The side portion 3 and the side portion 7 are approximately the same size. The side portion 5 and the side portion 9 are approximately the same size. In the unfolded state, the side portion 3 is connected to the side portion 5, and the side of the side portion 5 opposite to the side portion 3 is connected to the side portion 7. The side of the side portion 7 opposite to the side portion 5 is connected to the side portion 9 (see Figures 3 and 4). A handle portion 30 is provided in the center of the side portion 5 and the side portion 9, and is defined by a substantially U-shaped cut line. The handle portion 30 is pushed inward during use to become the handle of the packaging box 10.

[0020] An adhesive margin 21 is connected to the side of side portion 3 opposite side portion 5. In addition, an adhesive portion 22 is provided at the end of side portion 9 opposite side portion 7. The adhesive margin 21 is a portion that is fixed to the adhesive margin 22 by a known fixing method when folding the sheet material 1 to assemble the packaging box 10. The main body portion 2 is formed by fixing the adhesive margin 21 to the adhesive margin 22. The adhesive margin 21 and the adhesive margin 22 are crushed so that they are thinner than other portions, and when the adhesive margin 21 and the adhesive margin 22 are fixed, this portion is prevented from becoming thicker than other portions.

[0021] Vertical creases 20 for facilitating folding are provided between the side surface portions 3, 5, 7, and 9. Vertical creases 20 are also provided between the side surface portion 3 and the adhesive margin portion 21.

[0022] A flap 23 extends from the opening edge 33a on the opening A side of the side surface portion 3 in a direction intersecting the direction in which the side surface portions 3, 5, 7, and 9 are arranged (see FIG. 4). Hereinafter, in FIGS. 3 and 4, the direction in which the side surface portions 3, 5, 7, and 9 are arranged will be referred to as the longitudinal direction of the sheet material 1, or simply as the longitudinal direction.

[0023] Flap 25 extends from opening edge 35a on the same side as opening edge 33a of side surface portion 5, similar to flap 23. Furthermore, flap 27 extends from opening edge 37a on the same side as opening edge 33a of side surface portion 7, similar to flap 23. Furthermore, flap 29 extends from opening edge 39a of side surface portion 9, similar to flap 23. Hereinafter, the side of the flap opposite to side surfaces 3, 5, 7, and 9 will also be referred to as the "front side." Furthermore, the side of the flap facing side surfaces 3, 5, 7, and 9 will also be referred to as the "base side." Approximately in the center of flap 27, there is provided an opening portion 40 defined by a convex cut line. The opening portion 40 is pushed inward or cut away during opening, and is the portion that the user places their hand on to open the package.

[0024] Flaps 25, 29 are inner flaps that are folded inward along opening edges 35a, 39a to close at least a portion of opening A. As shown in Figures 3 and 4, leading edge 45 of flap 25 is bent in a crank shape, and flap 25 has a generally L-shaped configuration in which the width in the up-down direction on the flap 27 side is narrower than that on the flap 23 side (see Figures 3 and 4).

[0025] A leading edge 49 of the leading end of flap 29 is bent in a crank shape, and flap 29 has a generally L-shaped configuration in which the width in the vertical direction on the flap 27 side is narrower than the side that will be adjacent to flap 23 when main body 2 is assembled (see Figures 3 and 4). In other words, flaps 25 and 29 are formed so that the portion corresponding to opening portion 40 is cut out when opening A is closed.

[0026] The flaps 23 and 27 are outer flaps that are folded inward along the opening edges 33a and 37a to close the opening A and are disposed outside the flaps 25 and 29 (see FIG. 2). A leading edge 43 of the flap 23 extends substantially parallel to the opening edge 33a. A leading edge 47 of the flap 27 extends substantially parallel to the opening edge 37a.

[0027] The flaps 23 and 27 are sized to cover substantially the entire opening A together, without their respective leading ends overlapping when closed. Specifically, the lengths of the flaps 23 and 27 in a direction intersecting the longitudinal direction of the sheet material 1 are set so that, when closed, the leading edges 43 and 47 abut against each other or a gap is formed between the leading edges 43 and 47. In other words, the flaps 23 and 27 are arranged such that the sum of their respective lengths in the up-down direction in Figures 3 and 4 is substantially the same as or slightly shorter than the length of the side surface portions 5 and 9 in the longitudinal direction of the sheet material 1.

[0028] A flap 53 extends in the opposite direction to the flap 23 from the opening edge 33b on the opening B side of the side surface portion 3. Similarly, a flap 55 extends from the opening edge 35b of the side surface portion 5, a flap 57 extends from the opening edge 37b of the side surface portion 7, and a flap 59 extends from the opening edge 39b of the side surface portion 9, similar to the flap 53. Hereinafter, the opening edges 33a, 35a, 37a, 39a and the opening edges 33b, 35b, 37b, 39b will also be collectively referred to as the "opening edges 33, 35, 37, 39."

[0029] The flaps 55, 59 are inner flaps that are folded inward along the opening edges 35b, 39b to close at least a portion of the opening B. A leading edge 65 of the flap 55 extends substantially parallel to the opening edge 35b. Furthermore, a leading edge 69 of the flap 59 extends substantially parallel to the opening edge 39b.

[0030] The flaps 53 and 57 are outer flaps that are folded inward along the opening edges 33b and 37b when the opening B is closed, and are disposed outside the flaps 53 and 57. A leading edge 63 on the leading side of the flap 53 extends substantially parallel to the opening edge 33b. Furthermore, a leading edge 67 on the leading side of the flap 57 extends substantially parallel to the opening edge 37b.

[0031] The flaps 53 and 57 are sized so that, when closed, their leading ends do not overlap, and the flaps 53 and 57 cover substantially the entire opening B. Specifically, the lengths of the flaps 53 and 57 in a direction intersecting the longitudinal direction of the sheet material 1 are set so that, when closed, the leading edges 63 and 67 abut or leave a gap between them. In other words, the flaps 53 and 57 are arranged such that the sum of their respective lengths in the up-down direction in Figures 3 and 4 is substantially the same as or slightly shorter than the length of the side portion 5 and the side portion 9 in the longitudinal direction of the sheet material 1.

[0032] The sheet material 1 has ruled lines 15 formed on its inner surface at positions corresponding to the opening edges 33, 35, 37, and 39 (see Fig. 4). The ruled lines 15 are linear depressions formed by a known method, and are continuous linear depressions extending toward the outer surface by a predetermined depth (see Figs. 5 and 6). In other words, the ruled lines 15 are linear depressions formed toward the outside by a predetermined width using a known method.

[0033] A set of creases 11 and 13 extending in the longitudinal direction of the sheet material 1 is provided near the opening edges 33, 35, 37, and 39 on the outer surface of the sheet material 1 (see Figure 3). The creases 11 and 13 are linear depressions formed by a known method, and are continuous linear depressions that extend to a predetermined depth toward the back surface, i.e., the inner surface (see Figures 5 and 6). In other words, the creases 11 and 13 are linear depressions that extend to a predetermined depth toward the inside of the sheet material 1, with a predetermined width, using a known method.

[0034] The crease 11 is provided closer to the side surfaces 3, 5, 7, and 9 than the opening edges 33, 35, 37, and 39, and extends parallel to the opening edges 33, 35, 37, and 39. The crease 13 is provided on the opposite side of the opening edges 33, 35, 37, and 39 from the crease 11, and extends parallel to the opening edges 33, 35, 37, and 39.

[0035] Depressions 17 are provided on the inner surface of the sheet material 1 at positions a predetermined distance forward from the opening edges 33, 35, 37, and 39. The depressions 17 are strip-shaped depressions having a predetermined width and provided parallel to the opening edges 33, 35, 37, and 39. The depressions 17 are provided forward of the positions corresponding to the ruled lines 13 on the outer surface (see Figures 5 and 6).

[0036] 2. Explanation of the tip of the flap Next, the shape of the tip side of flaps 23, 27, 29 and flaps 53, 55, 57, 59 will be described using flap 23 as an example, mainly with reference to Figures 5 and 6. Note that for the purpose of explanation, Figures 5 and 6 illustrate the angle of inclination of the outer and inner surfaces, the depth and dimensions of the recesses, and other characteristics in a manner that makes them clearer, but the angle of inclination, the depth and dimensions of the recesses, and other characteristics are not limited to these.

[0037] The front portion of the outer surface of the flap 23 is formed so as to slope inward as it moves toward the front from a first start position 70 that is a predetermined distance away from the front edge 43 toward the opening edge 33a. In addition, a recessed line portion 73 extending parallel to the front edge 43 is provided in the vicinity of the front edge 43 of the flap 23 and at a position that is a predetermined distance away from the opening edge 33a (see FIGS. 3, 5, and 6).

[0038] The depression line portion 73 is a linear depression that is depressed inward. In other words, the depression line portion 73 is a portion that is linearly depressed inward by a predetermined depth with a predetermined width. In this embodiment, the depression line portion 73 is provided at a position approximately 5 mm away from the front side edge 43 toward the opening side 33a, as will be described below. However, the depression line portion 73 may be provided at a position other than the above as long as it is near the front side edge 43. The inclined outer surface region from the first start position 70 to the depression line portion 73 is the first inclined portion 71.

[0039] On the outer surface, a first tip portion 75 is provided between the recessed line portion 73 of the flap 23 and the tip side edge 43, extending toward the tip side and inclining at an angle different from that of the first inclined portion 71. In other words, the first tip portion 75 is a portion that is further forward than the recessed line portion 73 and is crushed in a different direction from the recessed line portion 73.

[0040] The front portion of the inner surface of the flap 23 is formed so as to slope outward as it moves toward the front side from a second start position 80 that is a predetermined distance away from the front side edge 43 toward the opening edge 33a.

[0041] A band-shaped second tip portion 79 of a predetermined width extending parallel to the tip edge 43 is provided at the tip end of the inner surface of the flap 23. The second tip portion 79 is provided adjacent to the tip edge 43 in a portion further forward than the recess line portion 73. The second tip portion 79 extends toward the tip side at a different angle from the second inclined portion 77, the details of which will be described later. The second tip portion 79 is a portion that is crushed in a different direction from the recess line portion 73.

[0042] The area between the second start position 80 and the second tip portion 79 is the second inclined portion 77. The second start position 80 is located further forward than the first start position 70 (see FIGS. 5 and 6). In other words, the first inclined portion 71 is inclined more inwardly from the opening side 33a toward the tip than the second inclined portion 77.

[0043] In this embodiment, the second tip portion 79 has a width of approximately 3 mm, but the width may be different. While Fig. 5 illustrates the second tip portion 79 extending at an inward angle, the angle at which the second tip portion 79 extends is not limited to this. For example, the second tip portion 79 may extend in approximately the same direction as the portion of the flap 23 on the opening edge 33 side (see Fig. 6), or may be inclined at another angle.

[0044] In this embodiment, the first inclined portion 71, the recessed line portion 73, the first tip portion 75, the second inclined portion 77, and the second tip portion 79 are similarly provided on the tip sides of the flaps 27, 29, 53, 55, 57, and 59, respectively. Note that the flaps 55 and 59 may not be provided with the first inclined portion 71, the recessed line portion 73, the first tip portion 75, the second inclined portion 77, and the second tip portion 79. Alternatively, the flap 25 may also be similarly provided with the first inclined portion 71, the recessed line portion 73, the first tip portion 75, the second inclined portion 77, and the second tip portion 79. In other words, all the flaps may be provided with the first inclined portion 71, etc.

[0045] 3. Evaluation test of packaging boxes The following shows the results of a comparison test conducted to evaluate the performance of the packaging box 10 according to this embodiment with a conventional packaging box. In the following tests, the samples shown in the table below were used to conduct the respective tests (see Table 1). [Table 1]

[0046] Sample (1) is a conventional packaging box having the same shape as packaging box 10, but with only ruled lines 11, 13 and a recessed portion 17. In other words, it is a conventional packaging box that does not have any structure corresponding to first inclined portion 71, recessed line portion 73, first tip portion 75, second inclined portion 77, or second tip portion 79 on the tip side of the flap. Sample (2) is a packaging box identical to packaging box 10.

[0047] Sample (3) is a packaging box having the same characteristics as packaging box 10. Note that sample (3) differs from sample (2) in the length of flaps 23 and 25. Specifically, flaps 23 and 25 of sample (3) are long enough that leading edge 43 and leading edge 47 abut when they are closed. Sample (4) is a conventional packaging box having the same shape as sample (3), but does not have on its flaps any configurations corresponding to lines 11 and 13, recessed portion 17, first inclined portion 71, recessed line portion 73, first leading portion 75, second inclined portion 77, and second leading portion 79.

[0048] 3-1 Sealing performance test Using sample (3) and sample (4), a test was conducted in which the flaps were secured with adhesive tape while the top and bottom openings of each were closed, and the heights were compared after that (see Figure 7). The measurement results are shown in the table below (see Table 2). The test was conducted on empty boxes with no contents inside, with 50 samples of each type. Each sample, with its opening closed with a flap and secured with adhesive tape, was placed near a wall, and the height of each packaging box was measured and the average value calculated. Note that the reference value in the table below is the calculated value for the height of the packaging box in the closed state, taking into account the thickness of the cardboard sheet.

[0049] The height of the packaging box in the closed state will be close to the standard value if the resilience of the cardboard sheet is suppressed. On the other hand, if the resilience of the cardboard sheet is not suppressed, the measured value will be large. In other words, the results of this test can confirm the extent to which the resilience of the cardboard sheet is suppressed. [Table 2]

[0050] As shown above, the difference from the reference value was smaller for sample (3), which is the packaging box 10 according to this embodiment, compared to sample (4), which is a conventional packaging box. That is, it is shown that the packaging box 10 of this embodiment suppresses the repulsive force of the cardboard sheet, and maintains fixation with adhesive tape with little bulging.

[0051] 3-2 Overlap test during sealing In this test, samples (3) and (4) were used to check the percentage of packaging boxes that were closed with the tips of the outer flaps overlapping when the top and bottom openings were closed with flaps using a sealing machine and secured with adhesive tape. The measurement results are shown in the table below (see Table 3). The test was conducted on empty boxes with no contents inside, with 50 samples for each, and the number of packaging boxes that were secured with the tips of the outer flaps overlapping was counted. [Table 3]

[0052] In sample (4), which is a conventional packaging box, approximately half (26 boxes) were closed with the tips of the outer flaps overlapping and secured with adhesive tape. That is, the rate of packaging boxes secured in this state was approximately 52%. On the other hand, in sample (3), which is the packaging box 10 of this embodiment, there were four packaging boxes in this state, and the rate of this state was approximately 8%. That is, it was shown that the packaging box 10 of this embodiment is able to prevent the tips of the outer flaps from being secured in an overlapping state when sealing.

[0053] This is thought to be because in the packaging box 10, at least the outer flaps 23, 27, 53, and 57 are provided with the first tip portion 75 and the second tip portion 79, which further weakens the repulsive force at the tip side of the flaps, preventing such overlapping. In other words, even if the tip sides of the flaps overlap, the first tip portion 75 or the second tip portion 79 at the tip side of the flaps may deform, or the force may be dispersed at the first tip portion 75 or the second tip portion 79, causing the tip sides of the flaps to shift, eliminating the overlapping.

[0054] 3-3 Stability confirmation test when stacked A 1 L water bag was placed in each of samples (1) to (4), and the flaps were closed and fixed with adhesive tape. The samples were then stacked on top of each other and the appearance was checked.

[0055] The test results are shown in Figures 8(a) to 9(b). In sample (4), which is a conventional packaging box, it was confirmed that each packaging box was tilted and stacked in an unstable state (see FIG. 9(b)). On the other hand, in samples (2) and (3), which are packaging boxes 10 of this embodiment, it was confirmed that each packaging box was less tilted and stacked in a stable state (see FIGS. 8(b) and 9(a)). That is, in the packaging box 10 of this embodiment, the repulsive force of the cardboard sheet is reduced and the tips of the outer flaps are prevented from closing in an overlapping state, so the surface closed by the flaps is maintained in a flatter state. This shows that multiple packaging boxes 10 can be stacked in a stable state.

[0056] It was also confirmed that sample (1) was stacked in a more stable state than sample (4), a conventional packaging box. In sample (1), the lines 11 and 13 and the recessed portion 17 are provided, and it is thought that these configurations also reduce the repulsive force of the cardboard sheet of the flap to a certain extent, and the surface closed by the flap is maintained in a flat state to a certain extent.

[0057] 3-4 Comparison of appearance after sealing Samples (3) and (4) were closed and secured with adhesive tape, and a test was conducted to compare their appearances. It was confirmed that, in sample (4), a conventional packaging box, the outer flaps 23a and 27a were tilted upward toward the boundary where the tips of the two flaps faced each other due to the repulsive force of the cardboard sheet. Furthermore, it was confirmed that corner C at the tip of flap 27a was protruding outward due to the repulsive force (see Figure 10(a)).

[0058] On the other hand, in sample (3), which is the packaging box 10 of this embodiment, it was confirmed that the repulsive force of the flaps 23 and 27 was suppressed, and the inclination toward the boundary between the two flaps was suppressed. In other words, it was confirmed that the flaps 23 and 27 were fixed in a flatter state compared to sample (4). It was also confirmed that the corner portions C at the tips of the flaps did not protrude, and that the surfaces were fixed with adhesive tape in a smooth state (see FIG. 10(b)).

[0059] 4. About the effects According to the packaging box 10 configured as described above, the outer surface of the leading end of the flap is formed so as to slope inward toward the leading end, and is provided with a first inclined portion 71, a recessed line portion 73, and a first leading end portion 75. Similarly, the inner surface of the leading end of the flap is formed so as to slope outward toward the leading end, and is provided with a second inclined portion 77 and a second leading end portion 79.

[0060] That is, the tip portion of the flap has an outer surface and an inner surface that are inclined so that its thickness gradually becomes thinner toward the tip than toward the opening edge 33, and is formed in a flattened shape to form a predetermined shape.

[0061] This weakens the repulsive force at the tip of each flap, allowing the closed flaps to be closed and fixed in a flatter state compared to conventional packaging boxes. Furthermore, because the first tip 75 and the second tip 79 are provided further forward than the recessed line 73, and the repulsive force at the tip end of the flaps is weakened, the corners at the tips of the flaps 23, 27, 53, and 57 are likely to deform when the closed flaps are fixed with adhesive tape. In other words, when the closed flaps are fixed with adhesive tape, the corners of the outer flaps are prevented from protruding outward.

[0062] Therefore, compared to conventional packaging boxes, the packaging box can be closed and fixed in a flatter state. Also, multiple packaging boxes can be stacked in a more stable state. Furthermore, because the repulsive force on the tip side of the flap is weakened, it is expected that, for example, when putting contents into the packaging box 10, the contents will not hit the tip of the open flap and be damaged.

[0063] Furthermore, because the resilience of the leading ends of the flaps is weakened, even if the leading ends of the flaps overlap when closing the packaging box 10, the leading portions of the flaps deform, and the overlap is likely to naturally disappear. For example, when the flaps 23 and 27 are closed, the state in which the inner surface of the leading end of the flap 23 overlaps the outer surface of the leading end of the flap 27, i.e., the second leading portion 79 of the flap 23 overlaps the first leading portion 75 of the flap 27, will be described as an example. In this case, the first leading portion 75 and the second leading portion 79 are located further forward than the recessed line 73, further weakening the resilience of the cardboard sheet. Therefore, the force of closing the flaps deforms the leading portions of the overlapping flaps, causing the flaps 23 and 27 to shift, and the overlap at their leading portions is likely to disappear. In other words, the second leading portion 79 of the flap 23 and the first leading portion 75 of the flap 27 can be prevented from being fixed in an overlapping state.

[0064] Therefore, when the packaging box 10 is sealed using a sealing machine, for example, it is possible to provide a packaging box in which the leading ends of the flaps are less likely to be fixed in an overlapping state compared to conventional packaging boxes. Also, compared to conventional packaging boxes, the packaging box can be closed and fixed in a flatter state, and packaging boxes can be stacked in a more stable state.

[0065] Furthermore, the first tip portion 75 is formed to extend at an angle different from that of the first inclined portion 71, and the second tip portion 79 is formed to extend at an angle different from that of the second inclined portion 77. By doing so, for example, even if the leading ends of the flaps overlap when closing the packaging box 10, the force is dispersed by the first tip portion 75 and the second tip portion 79, and the overlap tends to naturally disappear.

[0066] For example, the following description will be given taking as an example a state in which, when the flaps 23 and 27 are closed, the inner surface of the leading edge of the flap 23 overlaps the outer surface of the leading edge of the flap 27, i.e., the second leading edge 79 of the flap 23 overlaps the first leading edge 75 of the flap 27. In this case, since the first leading edge 75 and the second leading edge 79 are formed as described above, the force for closing the flaps, which is applied to the leading edges of the overlapping flaps, is easily dispersed. Furthermore, this force may cause the overlapping portions of the leading edges of the flaps to deform, which may cause the flaps 23 and 27 to shift and the overlap to be resolved. In other words, it is possible to prevent the second leading edge 79 of the flap 23 and the first leading edge 75 of the flap 27 from being fixed in an overlapping state.

[0067] Therefore, when the packaging box 10 is sealed using a sealing machine, for example, the leading ends of the flaps are less likely to be fixed in an overlapping state compared to conventional packaging boxes. Also, compared to conventional packaging boxes, the packaging box can be closed and fixed in a flatter state. Also, packaging boxes can be stacked in a more stable state.

[0068] Furthermore, the first inclined portion 71 extends at an angle from a portion closer to the base than the second inclined portion 77. In other words, the first start position 70 is located closer to the base than the second start position 80, and the tip portion of the outer surface of the flap is inclined over a wider range than the inner surface. This reduces the repulsive force of the flap, allowing the packaging box to be fixed in a flatter state when closed compared to conventional packaging boxes. This also makes it possible to stack packaging boxes in a more stable state.

[0069] Packaging box 10 also has a set of creases 11 and 13 on its outer surface. Also, crease 15 is provided on the inner surface at a position corresponding to opening edges 33, 35, 37, and 39, and each flap has a depression 17 on the outer surface at a position beyond crease 13. In packaging box 10, these configurations also reduce the repulsive force of the flaps.

[0070] Furthermore, the creases 11, 13, and 15 and the recesses 17 of the packaging box 10 make it easier to fold the flaps outward. In other words, the creases 11, 13, and 15 and the recesses 17 of the packaging box 10 reduce the force required to fold the flaps in the direction opposite to the closing direction (hereinafter also referred to as "outward folding force").

[0071] Specifically, because crease 13 is located close to depression 17, when the flap is folded outward, the flap bends at crease 13. At this time, depression 17 reduces the outward folding force when folding the flap outward at crease 13. Furthermore, because the outward folding force at crease 13 is smaller than the outward folding force at crease 11, the crease when folding the flap outward is at crease 13. In other words, when the flap is folded outward, the crease is prevented from crossing crease 11 and crease 13. Furthermore, because depression 17 is located on the inner surface of the flap, it does not affect the stacking pressure strength of packaging box 10.

[0072] The technical scope of the present disclosure is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit thereof. For example, the first inclined portion 71, the recessed line portion 73, the first tip portion 75, the second inclined portion 77, and the second tip portion 79 may be provided only on the flap that closes the upper opening. That is, the first inclined portion 71, the recessed line portion 73, the first tip portion 75, the second inclined portion 77, and the second tip portion 79 may be provided only on the flaps 23, 25, 27, and 29. Alternatively, the first inclined portion 71, the recessed line portion 73, the first tip portion 75, the second inclined portion 77, and the second tip portion 79 may be provided only on the outer flaps. That is, the first inclined portion 71, the recessed line portion 73, the first tip portion 75, the second inclined portion 77, and the second tip portion 79 may be provided only on the flaps 23, 25, 53, and 57. In this way, the packaging box 10 can be manufactured using a simple process. Alternatively, the first inclined portion 71, the recessed line portion 73, the first tip portion 75, the second inclined portion 77, and the second tip portion 79 may be provided on all the flaps. Furthermore, the ruled lines 11 and 13 and the recessed portion 17 may be provided only on the flaps 23, 25, 27, and 29. [Explanation of symbols]

[0073] 1...Sheet material 2...Main body 3, 5, 7, 9...Side portions 10, 10a... Packaging box 11, 13, 15... Ruled line 17... Depression 20...Vertical ruled line 21...Glue margin 22...Attachment area 23, 23a, 25, 27, 27a, 29, ... Flap 33a, 33b, 35a, 35b, 37a, 37b, 39a, 39b...Opening side 53, 55, 57, 59...Flaps 43, 45, 47, 49, 63, 65, 67, 69...Front side 71...First inclined portion 73...Depression line portion 75...First tip portion 77...Second slope part 79...Second tip part A,B...Opening part

Claims

1. a main body having a plurality of side surfaces connected in a cylindrical shape and an opening surrounded by the side surfaces; a plurality of flaps extending from respective opening edges of the side surface portion that are sides of the opening and that close at least a portion of the opening; A packaging box made of a cardboard sheet, The plurality of flaps comprise a set of inner flaps extending from each of a pair of side surfaces arranged at positions opposite each other and folded at the opening edge to close at least a part of the opening, and a set of outer flaps extending from each of the opening edges of another pair of side surfaces different from the side surface surfaces from which the inner flaps extend and folded at the opening edge to overlap the inner flaps folded at the opening edge to close at least a part of the opening, Each of the outer flaps has a front side edge extending substantially parallel to the opening side on the front side in the direction in which the outer flap extends; the opening is closed, the opening is closed, and the side surface of the main body portion faces the inside, and the side surface of the main body portion faces the outside opposite to the inside surface, The tip portion of the outer surface is provided with a recessed line portion recessed inward, extending substantially parallel to the tip side edge at a predetermined distance closer to the opening side edge than the tip side edge, a first inclined portion in a region closer to the opening side than the recessed line portion and extending inwardly as it slopes from the opening side edge toward the recessed line portion, and a first tip portion between the recessed line portion and the tip side edge, The tip portion of the inner surface is provided with a second inclined portion that extends outwardly as it approaches the tip side, and a second tip portion between the second inclined portion and the tip side edge, the second tip portion is provided on the tip side of the recess line portion, the first inclined portion extends inwardly from the opening edge side relative to the second inclined portion, When the outer flaps are folded inward at the opening edge, the leading edge of one of the outer flaps abuts against the other outer flap. packaging box.

2. the first tip portion extends toward the tip side at an angle different from that of the first inclined portion, The second tip portion extends toward the tip side at an angle different from that of the second inclined portion. The packaging box according to claim 1.

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